Technical Field
The present disclosure relates generally to communication systems; and, more particularly, to performing clear channel assessment (CCA) within single user, multiple user, multiple access, and/or MIMO wireless communications.
Description of Related Art
Communication systems support wireless and wire lined communications between wireless and/or wire lined communication devices. The systems can range from national and/or international cellular telephone systems, to the Internet, to point-to-point in-home wireless networks and can operate in accordance with one or more communication standards. For example, wireless communication systems may operate in accordance with one or more standards including, but not limited to, IEEE 802.11x (where x may be various extensions such as a, b, n, g, etc.), Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), etc., and/or variations thereof.
In some instances, wireless communication is made between a transmitter (TX) and receiver (RX) using single-input-single-output (SISO) communication. Another type of wireless communication is single-input-multiple-output (SIMO) in which a single TX processes data into RF signals that are transmitted to a RX that includes two or more antennae and two or more RX paths.
Yet an alternative type of wireless communication is multiple-input-single-output (MISO) in which a TX includes two or more transmission paths that each respectively converts a corresponding portion of baseband signals into RF signals, which are transmitted via corresponding antennae to a RX. Another type of wireless communication is multiple-input-multiple-output (MIMO) in which a TX and RX each respectively includes multiple paths such that a TX parallel processes data using a spatial and time encoding function to produce two or more streams of data and a RX receives the multiple RF signals via multiple RX paths that recapture the streams of data utilizing a spatial and time decoding function.
Clear channel assessment (CCA) is a process performed by a wireless communication device to determine whether or not a transmission may be made on a wireless communication channel. Current practices of performing CCA can result in low and inefficient usage of the wireless communication channel. There continues to be much room for improvement in performing CCA to improve spatial spectral efficiency within wireless communications.